DIFFERENTIAL HYPOTHALAMUS BETA CATENIN EXPRESSION IN RATS WITH DEFICIENT LACTATION.

NEIRA FJ; PENNACCHIO GE; MACKERN-OBERTI JP; SOAJE M; FANELLI MA; JAHN GA; VALDEZ SR

Congreso; XXXIV Reunión Científica Anual de la sociedad de Biología de Cuyo; 2016

Cadherins and catenins and their activation by Wnt proteins participate in reproductive processes and interact with PRL signaling. We examined whether changes in the expression of Wnt/catenin proteins are involved in lactationdeficiency of OFA hr/hr rats by focusing on the regulation of PRL secretion at the hypothalamic level. Our first objective was to characterize the pattern of expression of β-catenin during the transition between gestation and earlylactation in OFA rats compared with Sprague Dawley (SD, their strain of origin). OFA and SD rats were decapitated at 12.00 h on days 19 and 21 of gestation (G19, G21) or day 2 of lactation (L2). Serum PRL levels were measured by RIA, and β-catenin expression in the medial basal hypothalamus was determined by Western blot. Comparison of β- catenin expression through days under study, revealed that SD rats decreased β-catenin levels at G21 and reestablished their values at L2, while OFA rats decreased protein expression only at L2 (p  0.05). Comparison of β- catenin expression on the same reproductive day revealed that SD rats had significantly lower values than OFA rats at G21 (p 0.05) and higher values at L2 (p  0.05). In conclusion, SD rats diminished β-catenin protein expression at G21 while OFA reached the lowest expression at L2. These results suggest that OFA rats show altered β-catenin expression linked with an increased dopaminergic tone and impaired PRL release during lactation